Printing system

ABSTRACT

An example method for operating a printing system in accordance with aspects of the present disclosure includes receiving, at a printing unit, a print job, receiving, at the printing unit, a trigger generated by a finishing unit, and initiating the print job based on the generated trigger.

BACKGROUND

A printing device may have one or more finishing devices connected toit. The printing device comprises an output unit for outputting aprinted image to the finishing device when the finishing device isarranged at the printing device. When the printing device and thefinishing device share a portion of a common media path, there can amechanism (e.g. a conveyor belt) between the printing device and thefinishing device. A finishing device may be used to perform apost-printing operation, such as stacking, stapling, inserting, cutting,folding, booklet making and/or punching a pattern. For example, mediamay be fed directly from the printing device to an inline finishingdevice. After printing, the pages pass through a finishing deviceconnected to the printing device. The finishing device processes theprinted pages and may perform one or multiple finishing operations on apage. For example, the finishing device may collate the printed pagesinto separate groups and then staple each group together, may stackpages, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

Example implementations are described in the following detaileddescription and in reference to the drawings, in which:

FIG. 1 illustrates an example system in accordance with animplementation;

FIG. 2 illustrates an example block diagram of an example system inaccordance with an implementation; and

FIG. 3 illustrates an example process flow diagram in accordance with animplementation.

DETAILED DESCRIPTION

Various implementations described herein are directed to printing. Morespecifically, and as described in greater detail below, various aspectsof the present disclosure are directed to a manner by which a printingsystem with in-line finishing performs printing jobs.

Aspects of the present disclosure described herein proceed with a printjob submitted by a user if a trigger generated by a finishing device isreceived at the print job.

While processing a print job, the printing device and the finishingdevice may need to be synchronized for the finishing operation to becompleted accurately (e.g., the printed images are aligned correctly inthe finishing device's cycle as they arrive at the finishing device).Some printing devices physically mark pages to signal to a finishingdevice when to operate to complete the finishing operation requested ina print job. More specifically, a print job may instruct the finishingdevice to fold the printed sheets along a specific line on the pages.Accordingly, the pages may be marked to indicate to the finishing devicewhere the specific line is located. This may be achieved, for example,by providing a barcode on the printed sheets. A controller may beadapted to use synchronization markings (e.g. detected by one or moreoptical detectors placed in-line) made on a printed page for properoperation.

However, some finishing devices may not be able to recognize marks. Afinishing device may not have the ability to read any marks on the pagesand therefore may not be able to adjust frame to frame to align thefinishing device exactly on a specific line. A finishing device may beconfigured to operate on a fixed frame length. In another example, afinishing device may be able to adjust the alignment of the printedimages frame to frame by reading the marks on the pages, but theadjustment may be limited to up to a certain measurement (e.g.,fractions of an inch), and accordingly, the adjustment may occur veryslowly.

Accordingly, the finishing device may take a long time to reachsynchronization. According to various aspects of the present disclosure,the approach described herein allows a finishing device to generate atrigger to instruct a printing device to initiate printing at an exacttime (and accordingly at an exact point on the printed paper). Amongother things, this approach may prevent waste paper, increase securityof the content being printed by avoiding such content disclosed on wastepaper, decrease the amount of time needed to complete a print job, andreduce costs associated with printing.

In one example in accordance with the present disclosure, a method foroperating a printing system is provided. The method comprises receiving,at a printing unit, a print job, receiving, at the printing unit, atrigger generated by a finishing unit, and initiating the print jobbased on the generated trigger.

In another example in accordance with the present disclosure, a printingsystem is provided. The printing system comprises a printing unit toreceive a print job, and a controller to control input data generated inresponse to a trigger from a finishing unit. The finishing unit iscommunicatively coupled to the printing unit. The trigger initiates theprint job at the printing unit.

In a further example in accordance with the present disclosure, aprinting system is provided. The printing system comprises a printingunit to receive a print job. The printing unit receives a triggergenerated by a finishing unit within a predetermined amount of time andinitiates the print job based on the generated trigger

FIG. 1 illustrates an example printing system 100 in accordance with animplementation. The system 100 comprises a computer 110 with a userinterface 120, a printing device 130, and a finishing device 140, eachof which is described in greater detail below. It should be readilyapparent that the system 100 depicted in FIG. 1 represents a generalizedillustration and that other components may be added or existingcomponents may be removed, modified, or rearranged without departingfrom a scope of the present disclosure. For example, while the system100 illustrated in FIG. 1 includes only one user interface 120, thesystem may actually comprise a plurality of user interfaces, and onlyone has been shown and described for simplicity.

In one implementation, the printing system 100 may be a web-fed printingsystem. In another implementation, the printing system 100 may be adigital web printing system comprising a digital press with a web feed.The computer 110 may be a user device. It should be noted that thecomputer 110 is intended to be representative of a broad category ofdata processors. The computer 110 may include a processor and memory andhelp translate input received by a keyboard. In one implementation, thecomputer 110 may include any type of processor, memory or display.Additionally, the elements of the computer 110 may communicate via abus, network or other wired or wireless interconnection.

The computer 110 comprises a processor, and a machine readable mediumencoded with instructions, each of which is described in greater detailbelow. The components of the computer may be connected via buses. Thecomputer 110 may be any of a variety of computing devices, such as aworkstation computer, a desktop computer, a laptop computer, a tablet orslate computer, a server computer, or a smart phone, among others. Morespecifically, as non-limiting examples, the computer 110 may beconfigured as any type of personal computer, portable computer,workstation, personal digital assistant, video game player,communication device (including wireless phones and messaging devices),media device, including recorders and players (including televisions,cable boxes, music players, and video players) or other device capableof sending a print request to the printing device.

The processor may comprise at least one high-speed data processoradequate to execute program components for executing user and/orsystem-generated requests. The processor may retrieve and executeinstructions stored in the machine readable medium. The processor maybe, for example, a central processing unit (CPU), a semiconductor-basedmicroprocessor, an application specific integrated circuit (ASIC), afield-programmable gate array (FPGA) configured to retrieve and executeinstructions, other electronic circuitry suitable for the retrieval andexecution instructions stored on a computer readable storage medium, ora combination thereof. The processor may fetch, decode, and executeinstructions stored on the machine readable medium to operate thecomputer 110 in accordance with the above-described examples. Themachine readable medium may be a non-transitory computer-readable mediumthat stores machine readable instructions, codes, data, and/or otherinformation. The instructions, when executed by a processor (e.g., viaone processing element or multiple processing elements of the processor)can cause the processor to perform processes described herein.

In certain implementations, the machine readable medium may beintegrated with the processor, while in other implementations, themachine readable medium and the processor may be discrete units.

Further, the computer readable medium may participate in providinginstructions to the processor for execution. The machine readable mediummay be one or more of a non-volatile memory, a volatile memory, and/orone or more storage devices. Examples of non-volatile memory include,but are not limited to, electronically erasable programmable read onlymemory (EEPROM) and read only memory (ROM). Examples of volatile memoryinclude, but are not limited to, static random access memory (SRAM) anddynamic random access memory (DRAM). Examples of storage devicesinclude, but are not limited to, hard disk drives, compact disc drives,digital versatile disc drives, optical devices, and flash memorydevices.

In one implementation, the machine readable medium may have print jobdatabases. These databases may store data such as print job request IDs,the names of documents to be printed, and the time of the printingrequest and/or the like.

As discussed in more detail above, the processor may be in datacommunication with the machine readable medium, which may include acombination of temporary and/or permanent storage. The machine readablemedium may include program memory that includes all programs andsoftware such as an operating system, user detection software component,and any other application software programs. The machine readable mediummay also include data memory that may include system settings, a recordof user options and preferences, and any other data required by anyelement of the computer 110. The computer readable medium may includeprogram memory that includes all programs and software such as anoperating system, user detection software component, and any otherapplication software programs. The computer readable medium may alsoinclude data memory that may include system settings, a record of useroptions and preferences, and any other data required by any element ofthe computer 110.

In one implementation, the machine readable storage medium (media) mayhave instructions stored thereon/in which can be used to program thecomputer 110 to perform any of the processes of the implementationsdescribed herein. For example, one type of instructions may be receivinginstructions. The receiving instructions can cause the processor toreceive data regarding a printing request from the user 150. Theprinting request may include the user ID, the name of the document, thespecifics of the print job (e.g., number of copies, operations for thefinishing device).

In another implementation, the processor may receive data from theprinting device 130 and/or the finishing device 140. For example, afteran instruction to proceed with a print job received from a user of thesystem 100, the printing device may issue an error for a plurality ofreasons (e.g. time out, missing trigger from the finishing device). Inresponse to the error received from the printing device, the processormay instruct to display an alert on the user interface 120 to inform theuser 150 about the existing error.

In one implementation, the user interface 120 may be a display of thecomputer 110. The user interface 120 may refer to the graphical, textualand auditory information a computer program may present to the user 150,and the control sequences (such as keystrokes with the computerkeyboard) the user 150 may employ to control the program. In one examplesystem, the user interface 120 may present various pages that representapplications available to the user 150. The user interface 120 mayfacilitate interactions between the user 150 and computer system 100 byinviting and responding to user input and translating tasks and resultsto a language or image that the user 150 can understand. In anotherimplementation, the computer 110 may receive input from a plurality ofinput devices, such as a keyboard, mouse, touch device or verbalcommand.

As explained above in more detail, in some implementations, the user 150may interact with the system 100 through the user interface 120 bycontrolling a keyboard, which may be an input device for the computer110. The user 150 may perform various gestures on the keyboard. Suchgestures may involve, but not limited to, touching, pressing, waiving,placing an object in proximity.

In other implementation, the user 150 may interact with the system 100by controlling operation panels for the printing device 130 and/or thefinishing device 140. More specifically, the user 150 may operate anoperation panel associated with the devices to specify a web size, afinishing method, etc. to execute the finishing operation. The operationpanel may comprise an information input key used to input information onfinishing operations such as the size of printing to be finished and afinishing mode, a finishing execution key used to start the finishingprocess, and a position fine-tuning key used to fine-tune the positionsof the web.

In one implementation, the user 150 may choose to press at least one keyon the keyboard to request a print job to be processed by the printingsystem 100. In response to detected pressing, the printing system mayinitiate the print job. For example, a printer driver program installedin and executed by the computer 110 may be used. The printer driverprogram may be read from a floppy disk or a CD-ROM and then installed inthe computer 110 or may be downloaded from a server via the Internet orthe like and then installed in the computer 110. When the printer driverprogram installed in the computer 100 is activated, a printer driverscreen may be displayed on the user interface 120.

The printing device 130 may be a printing assembly, such as, a web fedpress, for example a digital press, which outputs web of a single printjob (or of multiple print jobs). The printing device 130 and thefinishing device 140 may have a smart interface for connecting theprinting device 130 and the finishing device 140, thereby extending thecontrol of the printing device 130 to the finishing device 140. Theprinting device 130 may receive a print job.

In one example, the finishing device 140 is a separate module that iscoupled to the printing device 130. The finishing device 140 may be adevice to perform finishing operations. For example, the finishingdevice may be a unit for cutting and folding a printed web intopredetermined printing images. The finishing device 140 may be designedto carry out one or more finishing actions, such as, for example,scoring, cutting, slitting, trimming, folding and binding. Examples oftypes of finishing devices may include a folder, a booklet maker, a wirebinder, a book binder, a top feed, and/or alike.

The finishing device 140 may be mechanically attached to the printingdevice 130 in order to receive the printed materials from the printingdevice 130. The finishing device 140 may also be electrically connectedto the printing device 130 in order to receive instructions forperforming the finishing operations from the printing device 130. In oneexample the finishing device 140 may perform only one finishingoperation. For example, the finishing device 140 may only staple theprint job that it receives from the printing device 130. In anotherexample, the finishing device 140 may be capable of performing more thanone finishing operation. For example, the finishing device 140 may bothstaple and stack the print job that it receives from the printing device130. Further, the finishing device 140 may perform one set of finishingoperations but, optionally, may perform another set of finishingoperations at the direction of the user 150 or the printing device 130.For example, the finishing device 140 may stack print jobs that itreceives from the printing device 130, but may optionally staple theprint job or not staple the print job.

The finishing operations may be engaged or disengaged eithermechanically, electrically, or both by the printing device 130. Forexample, the user 150 may connect the finishing device 140 to theprinting device 130 by mechanically attaching the finishing device 140to the printing device 130. The user 150 may align and mate the twodevices in such a manner that the finishing device 140 is capable ofreceiving a print job from the printing device 130. Additionally, theuser 150 may electrically connect the printing device 130 and thefinishing device 140 to supply power to the finishing device 140, sendand receive electrical signals that activate or deactivate the finishingoperation, or indicate when errors occur during the finishing of theprint job. Not only may communication between the printing device 130and the finishing device 140 may occur through the electricalconnection, but communication may also occur through an opticalconnection, such as a fiber optic cable or infrared beam, or through awireless connection, such as the Bluetooth wireless connection, familiarto those of ordinary skill in the art.

In one implementation, the printing device may receive a print job, forexample, from the computer 110 via the user 150. In one implementation,the finishing unit 140 may receive a notice of the print job, and thismay initiate the transmission of a trigger to the printing device 130.The printing device 130 may not initiate the print job until a triggeris received from the finishing device 140. The trigger is to initiatethe print job, and accordingly, the printing device starts the print jobonly when the trigger is received from the finishing device 140. Inanother implementation, the receipt of the print job may not becommunicated to the finishing device 140. In one implementation, theprinting device 130 may wait for a set amount of time to receive atrigger from the finishing device 140. Such amount of time may be setand calibrated to assure alignment of the pages being processed by theprinting device 130 as they are received at the finishing device 140.For example, the finishing unit 140 may generate a cyclic trigger (e.g.,cyclically recurring signal) for each page to be printed by the printingdevice 130. Moreover, the timing of the trigger may need to becalibrated based on a cycle of the finishing device 140. The timing ofthe trigger may be calibrated to align the image printed by the printingdevice 130 in the finishing device's cycle when received at thefinishing device 140. The cycle of the finishing device may be definedas one loop of at least one finishing operation that the finishingdevice 140 performs based on the finishing operations indicated in theprint job.

The printing device 130 and the finishing device 140 may be placed a setdistance from one another. For example, the distance between two devicesmay be set to 26 feet. In one implementation, if the distance ischanged, the timing of the trigger generated by the finishing unit 140may need to be adjusted accordingly to maintain the alignment of theprinted images from the printing unit 130 when arriving at the finishingunit 140.

In one implementation, the printing device 130 may need to use aconversion module to receive an electrical signal from the finishingdevice 140. Conversion modules may be available by the vendor of theprinting device 130 or the finishing device 140. For example, thefinishing device 140 may generate a specific signal and send it to theprinting device 130 to initiate the print job requested by the user 150.Such electrical signal may act as a trigger to alert the printing device130 to proceed with the printing and may only be communicated if theproper conversion module exists in the printing system 100. It should benoted that the printing system 100 may achieve high precision using theelectrical signal as such real-time trigger provides real-timecommunication and interaction between devices in the printing system100.

The printing device 130 may be controlled by a controller, which will beexplained in more detail below in reference to FIG. 2. The controllermay receive information, via a communication line from the finishingdevice 140, for example, indicating whether the finishing device 140 ison-line or off-line. For example, if the finishing device 140 isoff-line, upon receiving information from the finishing device 140indicating that the finishing device 140 is off-line, the controller mayindicate on the user interface 120 or on the operation panel of theprinting device 130 that the finishing device 140 is off-line. Thecontroller of the printing device 130 may then notify the computer 110that the finishing device 140 is off-line, and that no images can beprocessed. Notified of this, the controller of the printing device 130may accept a spool of a print job from the computer 110 and reserve thestart instruction given to the printing device 130.

In another implementation, the finishing device 140 may be on-line, andthe print job may be started. However, during the finishing process, anerror may occur at the finishing device 140. This error may be signaledto the printing device 130 in order to interrupt the current printingand initiate a recovery process. A communication module may beconfigured to output an error message to the user 150 of the printingdevice 130. Further, the controller may control, when an error signal isreceived from the finishing device 140, and initiate a finisher errorrecovery procedure.

In one implementation, the printing device 130 may connect to anadditional finishing device. The attributes related to the printingdevice 130 may typically be included in software released by the vendorof the printing device 130. Adding another finishing device to theprinting device 130 whose attributes are not stored in the memory,however, may require the vendor to write, debug, and distribute a newsoftware release to support the added finishing device.

FIG. 2 illustrates an example block diagram illustrating aspects of aprinting system 200 in accordance with an implementation. Morespecifically, FIG. 2 shows the printing system 200 comprising a printingdevice 210 and a finishing device 220. It should be readily apparentthat the printing system 200 illustrated in FIG. 2 represents ageneralized depiction and that other components may be added or existingcomponents may be removed, modified, or rearranged without departingfrom a scope of the present disclosure.

The printing device 210 comprises a print job reception module 230 thatreceives a print job from the computer 110 that sends print jobscontaining print data and at least one finishing operation command(e.g., cutting). The printing device 210 comprises a printing module 240that prints on a print medium based on the print data contained in theprint job. Moreover, the printing device 210 comprises a printingcontroller 250 to control the communication between the printing device210 and the finishing device 220 in addition to the computer (e.g., thecomputer 110 as shown in FIG. 1). Further, the printing device 210comprises an output module 260 for outputting a printed image-receivingweb to the finishing device 220.

In one implementation, an interface may be configured for the printingdevice 210 to connect to the finishing device 220. The finishing device220 comprises a finishing module 270 that implements the operationsdefined in the print job. For example, the finishing module 270 may cutthe print medium. In one implementation, the finishing module 270 mayhave a plurality of cutting patterns. If the print job includes acutting operation including a plurality of types of cutting operationscorresponding to the plurality of cutting patterns, the finishing module270 may proceed with the cutting operation. More specifically, thefinishing module 270 may cut a printed roll of paper and cut the roll ofpaper partially (when a partial cut is indicated in the print job) orcompletely (when a full cut is indicated in the print job) based on thepaper cutting operation contained in the print job. In anotherimplementation, the finishing module 270 may have a fixed knife, amovable knife disposed substantially parallel to the fixed knife, adrive motor for driving the movable knife, and a position detectionsensor for detecting the position of the movable knife.

The finishing device 220 comprises a finishing controller 280, whichcontrols the finishing device 220 on the basis of information receivedfrom the printing device 210 via a signal line or information input froman operation panel associated with the finishing device 220. Thefinishing controller 280 may be used for interfacing the finishingdevice 220 with the printing device 210. In another implementation, thesystem may comprise a plurality of finishing devices, and the finishingcontroller 280 may be used for controlling one or more finishingdevices.

In one implementation, the finishing controller 280 controls thefinishing device 220 in accordance with a finishing command specified bythe print job. For example, the finishing controller 280 controls acopying operation on the basis of the information input from theoperation panel. Further, the finishing controller 280 controls aprinting operation performed by the printing device 210 on the basis ofimage information and control information input by the printingcontroller 250. More specifically, the finishing controller 280 controlsa signal generated by the finishing device 220 in response to the printjob received from the user of the printing system 200. The finishingcontroller 280 may communicate the generated signal to the printingdevice 210, which initiates the printing process.

Communication protocol between the printing device 210 and the finishingdevice 220 may be executed over a standard Ethernet connection or anyother suitable communication protocol. The communication protocol mayaddress generic synchronization and status messages exchange. Before aprint job starts, the printing device 210 may wait for a trigger fromthe finishing device 220 to start. Further, the communication protocolmay be utilized to output error messages if errors are detected duringprinting and finishing processes.

In one implementation, the printing system 200 may comprise anotification module (not shown in FIG. 2) that outputs a reportindicating the print medium was finished synchronized to the finishingoperation of the finishing module 270. Moreover, the notification modulemay output a report with a different notification pattern according tothe type of finishing command.

Turning now to the operation of the system 100, FIG. 3 illustrates anexample process flow diagram 300 in accordance with an implementation.It should be readily apparent that the processes illustrated in FIG. 3represents generalized illustrations, and that other processes may beadded or existing processes may be removed, modified, or rearrangedwithout departing from the scope and spirit of the present disclosure.Further, it should be understood that the processes may representexecutable instructions stored on memory that may cause a processor torespond, to perform actions, to change states, and/or to make decisions.Thus, the described processes may be implemented as executableinstructions and/or operations provided by a memory associated with asystem 100. Alternatively or in addition, the processes may representfunctions and/or actions performed by functionally equivalent circuitslike an analog circuit, a digital signal processor circuit, anapplication specific integrated circuit (ASIC), or other logic devicesassociated with the system 100. Furthermore, FIG. 3 is not intended tolimit the implementation of the described implementations, but ratherthe figure illustrates functional information that could be used todesign/fabricate circuits, generate software, or use a combination ofhardware and software to perform the illustrated processes.

The process 300 may begin at block 305, where a request for a print jobis received by the printing system from a user of the system. A printjob in the context of the an implementation relates to a complete printtask that includes the actual printing, which is carried out by aprinting device, and one or multiple finishing operations, which are tobe carried out by a finishing line devices. Print job instructions maybe provided in Job Definition Format (JDF). The process of receiving theprint job further involves the printing device receiving the jobspecification in the JDF communication and dividing the jobspecification command in to a series of printing device specificcommands (typically also in JDF format or JMF—Job Messaging format,which is part of the JDF specification and is also typically built inXML). As discussed in more detail above with respect to FIG. 1, the usermay submit the request for the print job through printing software. Theuser may be, e.g., a person such as an administrator of a computerand/or an automated machine capable of providing print job requests.

At block 310, the system receives a trigger from the finishing device.As part of the process, it may be determined whether the printing systemis set to be externally triggered. In the event that the system is notset to be externally triggered, the printing system proceeds to initiatethe print job without further communication with the finishing device.In the event that the system is set to be externally triggered, thesystem checks to see if the finishing device generates a trigger that iscommunicated to the printing device. In one implementation, the systemmay wait for a set period of time to receive a trigger from thefinishing device. For example, the set period of time may be 10 seconds.In that example, if a trigger is not received from the finishing devicein 10 seconds, the printing device proceeds to issue an error (e.g.,timeout). Such error may be communicated to the user of the printingsystem via the user interface. In the event that the trigger is receivedin 10 seconds, the process continues to block 315 as shown in FIG. 3.

After receiving the generated trigger from the finishing device, atblock 315, the system initiates the print job. In one implementation, afirst part (e.g., first page, a first set length of printing element) ofthe print job may be printed, and the system waits to detect the triggerat the finishing device to proceed with a next part (e.g., the nextpage, the next set of length of printing element). In such animplementation, the software running in the printing device may requirea trigger for each part (e.g., each page). In another implementation,the printing device may proceed with the entire print job afterreceiving the trigger and may not require any additional triggers fromthe finishing device to continue after the first part of the document.

It is then determined whether the print jobs are finished or whetherthere are more pending jobs. If there exists a new job the above stepsare repeated for the next job, else the process terminates.

The present disclosure has been shown and described with reference tothe foregoing exemplary implementations. It is to be understood,however, that other forms, details, and examples may be made withoutdeparting from the spirit and scope of the disclosure that is defined inthe following claims. As such, all examples are deemed to benon-limiting throughout this disclosure.

What is claimed is:
 1. A method for operating a printing system,comprising: receiving, at a printing unit, a print job; receiving, atthe printing unit, a trigger generated by a finishing unit; andinitiating the print job based on the generated trigger, wherein thetrigger synchronizes the printing unit with the finishing unit bycausing output of the print job to be aligned in a cycle of thefinishing unit when the output of the print job is received at thefinishing unit.
 2. The method of claim 1, wherein initiating the printjob based on the generated trigger further comprising comprises causingthe printing unit to print at least a portion of the print job.
 3. Themethod of claim 1, wherein initiating the print job based on thegenerated trigger further comprises performing an alignment correctionof output of the print job by the printing unit.
 4. The method of claim1, wherein receiving the trigger generated by the finishing unit furthercomprises receiving the trigger in a predetermined amount of time. 5.The method of claim 4, wherein the printing unit issues an error messageif the printing unit does not receive the trigger within thepredetermined amount of time after receiving the print job.
 6. Themethod of claim 1, wherein the printing unit receives the triggercyclically.
 7. The method of claim 1, wherein timing of the triggerreceived at the printing unit may be adjusted based on the cycle of thefinishing unit.
 8. The method of claim 7, wherein the finishing unitperforms at least one finishing operation indicated in the print job,and wherein the cycle of the finishing unit is one loop of the at leastone finishing operation.
 9. The method of claim 8, wherein the triggersynchronizes by aligning a start of output from the printing unit with astarting location of the finishing operation by the finishing unit. 10.The method of claim 8, further comprising receiving user input to makethe printing system externally triggered.
 11. The method of claim 1,further comprising determining whether the printing system is externallytriggered.
 12. A printing system, comprising: a printing unit to receivea print job; and a controller to control input data generated inresponse to a trigger from a finishing unit communicatively coupled tothe printing unit, the trigger initiating the print job at the printingunit, wherein the trigger synchronizes the printing unit with thefinishing unit by causing output of the print job to be aligned in acycle of the finishing unit when the output of the print job is receivedat the finishing unit.
 13. The system of claim 12, wherein the amount oftime the printing unit waits to receive the trigger after the print jobis received is set by an input received from a user of the printingsystem.
 14. The system of claim 12, wherein the controller gatherssystem information from the finishing unit.
 15. The system of claim 14,wherein the system information identifies whether the system isexternally triggered or not.
 16. A printing system, comprising: aprinting unit to receive a print job; the printing unit to receive atrigger generated by a finishing unit within a predetermined amount oftime; and the printing unit to initiate the print job based on thegenerated trigger, wherein the trigger synchronizes the printing unitwith the finishing unit by causing output of the print job to be alignedin a cycle of the finishing unit when the output of the print job isreceived at the finishing unit.
 17. The system of claim 16, wherein thefinishing unit is to store attributes related to the finishing unit inthe printing unit.
 18. The system of claim 16, wherein the finishingunit has a conversion module to generate the trigger and send thetrigger to the printing unit.